The invention relates to digital tape cartridges, and in particular, to a tape cartridge leader having improved performance characteristics for use in single reel tape cartridges.
It is a problem in single reel magnetic tape cartridges to provide a tape cartridge leader that implements all of the features necessary to reliably buckle and unbuckle the tape cartridge leader with the take-up leader, to guide the tape cartridge leader into the take-up reel and to enable the tape cartridge to lock the magnetic tape in place for transport and storage. Present solutions to this problem suffer from tape cartridge leader failures due to the conflicting requirements of all of these functions and the need to implement a plurality of features in close proximity to each other in a limited length of the tape cartridge leader.
Digital data is stored by tape drives on to magnetic tape media utilizing a variety of tape cartridge and tape cassette designs, but in all cases, the magnetic tape media is wound between a pair of tape reels as data is transferred to or from the magnetic tape media. In the art of data storage, the physical space required to store data is an important concern. Referring to FIGS. 1-2, to conserve space, tape drives often use the single reel tape cartridge design shown in FIG. 1, which utilizes a supply reel located within a removable tape cartridge (not shown) and a take-up reel 101 located within the tape drive 100.
After the tape cartridge is inserted into the tape drive 100, the magnetic tape media must be loaded into the tape drive 100. The loading operation includes connecting the magnetic tape media to the take-up reel 101 and winding the magnetic tape media to a start point or.read position adjacent a tape head 112. Various methods have been employed to make this connection. FIG. 2 illustrates one such method wherein the magnetic tape media connects to the take-up reel 101 via a buckle 200 between a tape cartridge leader 203 and a take-up leader 201. The tape cartridge leader 203 terminates the magnetic tape media at one end and consists of a strong flexible plastic strip that includes an ovular aperture 202 configured to mate with the take-up leader 201. The take-up leader 201 is a similar strong flexible plastic strip that attaches at one end to the take-up reel 101 using a pair of integrally formed flanges 206 and 207. The opposing end includes a stem 204 and a tab 205 designed to buckle with the ovular aperture 202 on the tape cartridge leader 203.
The take-up leader 201 also includes apertures 209, 210 and 208. When a tape cartridge is not present in the tape drive 100, the take-up leader 201 is wound around a plurality of guide rollers 102-105 in a curvilinear tape path and is secured in place by a rotating catch 106 that extends through the aperture 208. During operation of the tape drive 100, the catch 106 is rotated to an out of the way position to enable the tape drive to wind the magnetic tape media between the take-up reel 101 and the supply reel in the tape cartridge. In addition, the aperture 209 is used by the tape drive 100 to detect when the take-up leader 201 and the tape cartridge leader 203 are in an unbuckled position for ejection of the tape cartridge from the tape drive. The aperture 210 is configured so that the buckle 200, between the take-up leader 201 and the tape cartridge leader 203, aligns with the aperture 210 to reduce the effect of the added height of the buckle 200 during winding around the take-up reel 101.
In similar fashion, the tape cartridge leader 203 consists of a strong flexible plastic strip that includes an ovular aperture 202 that buckles with the stem 204 and tab 205 of the take-up leader 201 of the tape drive. To prevent the tape cartridge leader 203 from being wound entirely into the tape cartridge, beyond the reach of the take-up leader 201 in the tape drive, the tape cartridge is equipped with a rotating cartridge leader retention hook 214 which is fixed to the cartridge housing and that extends through rectangular-shaped aperture 212. In addition, a pair of guide xe2x80x9cwingsxe2x80x9d, each consisting of a rectangular-shaped extension in the width direction of the tape cartridge leader 203, follow corresponding guide tracks formed in the opposing supply reel flanges to guide the tape cartridge leader 203 into position, centered between the supply reel flanges. The guide wings are also used as a tape leader retention feature, since they engage stops formed in the guide tracks, to thereby limit the movement of the tape cartridge leader 203 into the tape cartridge.
There are reliability problems with the present design of the tape cartridge leader 203, due to the stress placed on the tape cartridge leader 203 by the wind and rewind operations. In particular, the guide wings can crack and separate from the tape cartridge leader due to the force exerted on the guide wings by the tape drive seating the guide wings against the stops of the guide tracks in the tape rewind operation. Furthermore, the rectangular shape of the guide wings can cause rewind failures, due to the corners of the leading edges of the guide wings becoming damaged and failing to align with the guide tracks. In addition, the relatively short but stiff section of the tape cartridge leader does not flex sufficiently to remain completely in contact with the tape guide rollers in the tape path during the tape wind and rewind operations. The magnetic tape can potentially slip out of the tape path due to the failure of the tape cartridge leader properly seat against the guide rollers. These tape cartridge leader failures can result in the tape cartridge being unusable by the tape drive and/or resulting in an expensive tape cartridge leader repair/replacement.
The present invention overcomes the problems outlined above and advances the art by providing a tape cartridge leader that has improved performance and reliability. The present tape cartridge leader comprises an elongated main body integrally formed between a first end and a second end. The first end connects to the magnetic tape media that is wound on the supply reel in the tape cartridge. The second end includes an ovular aperture that buckles with the stem and tab of the take up leader of the tape drive.
In the present tape cartridge leader, a flex relief aperture is provided in the tape cartridge leader, located in the body of the tape cartridge leader between the guide wings. This flex relief aperture enables the tape cartridge leader to bend in a tight radius as the tape cartridge leader is pulled around the tape guide rollers in the tape drive, thereby ensuring that the tape cartridge leader is properly seated on the tape guide rollers as it traverses the tape path in the tape drive. The flex relief aperture also reduces the possibility of cracks forming in the tape cartridge leader where the guide wings meet the body of the tape cartridge leader, which is a problem in existing tape cartridge leaders. The guide wings are also shaped with a lead in radius to reduce to possibility of damage to the guide wings. In addition, the trailing edge of the guide wings includes a lead in chamfer to aid in the guide wings engaging the guide track in the cartridge housing.
These modifications to the existing tape cartridge leader improve the performance and reliability of the tape cartridge leader by reliably providing tape cartridge leader flex, guide, stop, and buckling features.